Not sure if this is the correct place to put this post... but it crosses a few boundaries. Basically my tap water phosphate is 5-10ppm!!! (HOLY moly I hear you cry) I have been trying to dose N,K & trace to see if the plants soak up the phos. But there is too much. I'm suffering from various minor algae outbreaks on a regular basis, and my anubias are covered in green dusty algae. In an experiment I introduced API Phoszorb, within 12 hours my tank phosphate was down to 0.5-1ppm. (Its not a true experiment as I introduced Purigen at the same time - whilst the water is clearer, I'm unsure whether it will have an effect on plant growth) Since then the plants have noticeably improved, increase photosynthesis etc. I am wondering whether a high phosphate can have an inhibitory effect on some plant growth? My next difficulty is finding how long the Phoszorb will last. I don't want to be crippled with the expense of combating high tap phosphate levels. Any comments or experience to help me?